to get scared, to be frightened
Tom es demasiado estúpido para asustarse.
Tom is too stupid to be scared.
Debió asustarse mucho al ver te.
They must have been really scared when they saw you.
— Bardo, falsa crónica de unas cuantas verdades (2022)
Tenga cuidado al despertarla si está dormida, podría asustarse.
Be careful when waking her if she’s asleep; you could scare her.
— El guardián invisible (2017)
La señorita Rosinha podría asustarse.
Miss Rosinha might get scared.
— El Auto De La Compadecida (2000)
There's nothing to be afraid of.